SUMMARY ? PROJECT 2 The primary goal of this Program Project is to establish a quantitative and automated pipeline for the reconstruction and interpretation of highly complex cellular tomographic data. Here, we will focus on automatic tomographic reconstruction technology, extraction of various features from the tomograms, and the analysis of distribution patterns derived from the extracted features. Specifically, in Project 2 we propose to address three aims: Aim 1: Develop an expert system for real-time tomographic reconstruction Aim 2: Develop algorithms for automated feature extraction Aim 3: Develop approaches for the analysis of distribution patterns derived from extracted features These efforts complement and feedback from the highly synergistic team of PIs both of Project 1, that will focus on the experimentally guided optimization of data collection strategies and on development and implementation of tomogram quality assessment and validation techniques (Hanein & Penczek), and Project 3 (Ludtke) that focuses on development of quantitative tools for tomogram annotation through deep learning technology and sub-tomogram averaging as well as interactive visualization tools. !